Microelectromechanical systems (MEMS) devices are semiconductor devices with embedded mechanical components. MEMS devices include, for example, pressure sensors, accelerometers, gyroscopes, microphones, digital mirror displays, micro fluidic devices, and so forth. MEMS devices are used in a variety of products such as automobile airbag systems, control applications in automobiles, navigation, display systems, inkjet cartridges, and so forth. Capacitive-sensing MEMS device designs are highly desirable for operation in miniaturized devices due to their low temperature sensitivity, small size, and suitability for low cost mass production.
A microelectromechanical systems (MEMS) pressure sensor typically uses a pressure cavity and a membrane element, referred to as a diaphragm, that deflects under pressure. In some configurations, a change in the distance between two plates, where one of the two plates is the movable diaphragm, creates a variable capacitor to detect strain (or deflection) due to the applied pressure over an area. Process variation on critical design parameters, such as the width of a MEMS pressure sensor diaphragm, can affect the sensitivity of a pressure sensor. For example, a small difference in the width of a MEMS pressure sensor diaphragm can result in a large difference in sensitivity, relative to the predetermined nominal, or design, sensitivity for the pressure sensor. Accordingly, the sensitivity of each MEMS pressure sensor is typically calibrated individually. Individual calibration of MEMS pressure sensors undesirably increases costs associated with the pressure sensor and/or can introduce error in pressure measurements.